Joining dead polymers

ABSTRACT

DEAD POLYMERS, WHETHER LIQUID OR SOLID, WITH A MOLECULAR WEIGHT OF 1,000 TO 2,000,000, DERIVED AT LEAST IN PART FROM A DIENE MONOMER, ARE JOINED WITH HALOGENATED JOINING AGENTS TO PRODUCE A RUBBER OF GREATER MOLECULAR WEIGHT.   D R A W I N G

April 18, 1972 A. F. HALASA JoINING DEAD PoLYMERs 2 Sheets-Sheet 1 Filedoct. a. 1969 N Nm mw v m mw N ww mw o m m C u m r u A 3 `v w rw. o n ,N1 o .d d w o n w 3 o w md Q -oma om .0 D 0.o o.o O 5005425 umooe vmUnited States Patent O "ice U.S. Cl. 260--85.1 9 Claims ABSTRACT F THEDISCLOSURE Dead polymers, whether liquid or solid, with a molecularweight of 1,000 to 2,000,000, derived at least in part from a dienemonomer, are joined with halogenated joining 'agents to produce a rubberof greater molecular weight.

This application is a continuation-in-part of my application Ser. No.575,967 led Aug. 30, 1966 (now abandoned).

The invention relates to novel branched polymers and to a novel methodof making them. The term polymer is used herein to include bothhomopolymers and copolymers.

Rubbery polymers of diene monomers often are difficult to fabricate intouseful shapes and commercially practical products or are deficient inphysical properties desired for such shapes or products. Such polymersinclude homopolymers of conjugated dienes of 4 to 6 carbon atoms (eg.butadiene, piperylene, isoprene, 2,3-dimethylbutadiene) and copolymersthereof (e.g. butadiene-isoprene, piperylene-butadiene, etc.) andcopolymers of such conjugated dienes with isobutylene (butyl rubber),styrene, a hydrocarbon-substituted styrene such as methylstyrene andethylstyrene, copolymers of butadiene and isoprene with styrene or suchsubstituted styrenes, natural rubbers, chloroprene and copolymersthereof with butadiene and/ or isoprene and/or styrene or an EPDM rubber(i.e. a rubber in which ethylene and propylene are copolymerized with anunconjugated diene monomer of about 5 to 12 carbon atoms which may bedicyclopentadiene, cyclooctadiene, hexadiene1,4, methylene norbornene,ethylidene norbornene or other nonconjugated dioleiin. Block copolymersas well as other copolymers can be used. The foregoing include theso-called stereo rubbers which have been of great interest in recentyears, but the properties of most of these new synthetic rubbers havenot been completely satisfactory for all uses, as witness the widespreadpractice of blending such rubbers with natural rubbers or emulsion SBR.

n The stereo rubbers may be produced by polymerization of isoprene orbutadiene-1,3 by means of a catalyst which is a hydrocarbon-solublehydrocarbon derivative of an alkali metal, for example, an alkyl,alkenyl, cycloalkyl, cycloalkenyl, aryl or alkaryl derivative. Preferredlinear polymer of diene monomers is prepared by polymerization of aconjugated diolen containing 4 to 6 carbon atoms by means of alithium-hydrocarbon catalyst in the absence of air and moisture;copolymers of butadiene and isoprene or of either or both such diolenswith styrene or methylstyrene are produced by the same technique.

The preferred polymerization catalyst is n-butyllithium. Derivatives ofthe alkali metals (and particularly lithium, sodium and potassium) whichare catalysts include the ethyl, butyl, amyl, hexyl, cyclohexyl,Z-ethylhexyl, n-dodecyl, n-hexadecyl, allyl, benzyl,crotonyl,'cyclohexenyl, camphyl, isobornyl, phenyl, tolyl, xylyl,naphthyl and xenyl alkali metals as well as di-metal derivatives whichinclude derivatives of ethylene, trimethylene, tetramethyl- PatentedApr. 18, 1972 ene, decamethylene and octadecamethylene; 1,2- dimetalatedpropane, 1,4 dimetalated benzene, 1,5 dimetalated naphthalene, 1,2dimetalated 1,3 (diphenyl) propane, etc. The polymerizations are usuallycarried out at atmospheric pressure, but pressure greater and less thanatmospheric may be employed. The reaction is advantageously carried outin a hydrocarbon compound, preferably a non-ether and usually pentane orhexane, usually at an elevated temperature below the temperature of theboiling point of the solvent, but higher temperatures may be used andtemperatures as low as 70 C. or lower may be employed. A small amount ofthe catalyst is all that is required, and usually from about 0.001 toabout 0.5 gram of catalyst will be employed for each parts of themonomer. Such linear polymers are characterized by high 1,4-content(8S-95% of polymer derived from butadiene or isoprene), when produced ina hydrocarbon solvent. They are characterized by high linearity andnarrow molecular weight distribution. The vulcanizates of such polymersare characterized by excellent physical properties, including highresiliency, low hysteresis, excellent resistance to abrasion, low runingtemperatures and excellent flexibility and retention of other goodphysical properties at extremely low temperatures typical of the Arcticin winter, all in comparison with standard emulsion polymerizates, suchas commercial SBR. However, such lithium-catalyzed polymers are morecliicult to process in standard rubber equipment, such as Banburymixers, mills and tubers, as compared to natural rubber and conventional(emulsion) SBR, so that they are usually mixed with natural rubberand/or SBR for commercial use. Certain of such polymers produced bylithium catalysts also possess undesirable cold-flow properties.

There are other diene polymers produced by polymerization of butadieneand/ or isoprene with or without other monomers, eg., styrene, etc., bymeans of other catalysts. Polymers of lower 1,4-content are produced bylithium catalysts in the presence of Lewis bases. All such dienepolymers may be treated by the process of Vthis invention.

It is an object of the invention to overcome the disadvantages of anysuch polymers of diene monomers, to provide novel branched polymers ofhigh molecular weight having unexpectedly improved properties and toprovide a novel method of making the novel polymers.

The polymers used in the invention have the chemical compositions ofrubbers. Often they are liquids (having molecular weights of 1,000 to30,000) or soft rubbers (having average molecular weights up to about300,000), but useful results are obtained with polymers of highermolecular weights (as high as about 2,000,000). Rubbery products areobtained by joining polymers of such lower molecular weights.

In accordance with the invention, the polymer treated is a dead polymer,i.e. it is substantially entirely free of live ends and is no longeractive in polymerization reactions. A relatively low molecular weightdead polymer or copolymer derived at least in part from a diene monomer,is reacted with a halogen-containing joining agent which comprises asaturated or unsaturated, straightor branched-chain or cyclo-containingaliphatic hydrocarbon which includes one to twenty or iifty or morecarbon atoms per molecule or an aromatic hydrocarbon and which comprisesone, two, three or four or more halogens attached to terminal or othercarbon atoms, or the halogen or halogens may be on an aliphatic oraromatic siliconor tin-containing compound in which the halogen orhalogens are attached to such metal. The halogen or halogens of thejoining agent may be luorine, chlorine, bromine and/or iodine or amixture of halogens. The joining agent may comprise other active groups.Such active groups may or may not enter into the joining reaction. Suchactive groups include ketone, aldehyde,

3 ether, hydroxy, oxide, nitro-vinyl, ester, anhydride, amine, acid,thio, sulfonate, sulfide and unsaturated, etc. groups. The joiningaction is carried out in the presence of a hydrocarbon-soluble aliphaticor cyclic hydrocarbon compound of an alkali metal, preferably a lithiumcompound but it is commercially feasible to use sodium and potassiumcompounds. f

The joining agent may be a low molecular weight compound (e.g., ahalogen-containing lower alkyl halide) or a halogen-containing highmolecular weight compound such as a polymer (e.g., neoprene,polyvinylchloride, chlorinated rubber, etc.). Other examples aremethylbromide, ethyl chloride, ethyl bromide, ethylene dibromide, propylbromide, isopropyl chloride, l-iodopropane, formyl chloride, formyliodide, acetyl bromide, secondary butyl chloride, tertiary butylchloride, tertiary amyl bromide, ttoctyl chloride, 1,5 dichloropentaneand 1,5 dibromopentane, l-chloropropane, 2-chloropropane,l-chloro-n-butane, 2-chloro-n-butane, l-chloro-2-methylpropane, 2chloro-n-pentane, 2-chloro-3-methyl-n-butane, 2,3,4-trichloron-hexane,l-chloro norbornene, l-chloro alpha and beta pinenes, l-chlorocyclopentadiene, 1,2-dichloro cyclopentadiene, a mixture ofmonochlorinated or otherwise halogenated dodecanes, a polyvinyl chloridehaving a molecular Weight of up to about 1000 or more, allyl chloride,methallyl chloride, 3chlorobutenel, cyclohexyl chloride,1,4-dichlorocyclohexene, 4-chloro-cyclohexene, cycloheptyl chloride,propargyl chloride, styrylchloride, cyclohexylmethyl chloride,2-chloro-butadiene-l,3, l,2-dichlorobutane, 2,3dichloro-butane,1,2,3-trichlorobutane, 1,2,3,4 tetrachlorobutane, 1bromopropane,2-bromopropane, lbromo-n-butane, 2bromonbutane, 1-iodo-2-methylpropane,1,3-bromo-2-methylpropane, 2-iodo-n-pentane, 2,4- diiodo-n-pentane,2-bromo-3-methyl-n-butane, 2,3,4-tribromo-n-hexane, a mixture ofmono-brominated dodecanes, benzyl bromide, phenethyl bromide,l-phenyl-2- iodopropane, 2-(p-bromo-phenyl)-3-bromo-butane, allylbromide, methallyl iodide, 3 bromo-butene l, styrylbromide,bis(bromomethyl)benzene, 1,3,5 (tribromomethyl) benzene,bis(iodomethyl)-naphthalene, cyclohexyl bromide, 1,4 diiodo-cyclohexene,4 bromocyclohexene 1, cyclohexylmethyl iodide, cycloheptyl bromide,propargyl bromide and 2 iodobutadiene 1,3, bis(1 bromoethyl) ether, 1,3dichloro 2 propane, 1,5 dichloro 2,4 pentadione, bis(lfluoropropyl)ether, 1chloromethyl 4 (l chloro-n-propyl) benzene, 1,4 dichloro 2hexane, 4chloro2heptane, 2,5,6,9 tetrachloro 3,7 decadiene, bis( liodoamyl) ether, bis[1 chloro( 2 butyl)ethyl] ether, chloromethyl methylether, 1,2 dichlorobenzene, 1,3 dibromobenzene, l,4- dichlorobenzene, lchloro 4 bromobenzene, 1,3,5- trichlorobenzene, l,2,4,5tetrabromobenzene, hexachlorobenzene, 1,2 dichloronaphthalene, 1,4dibromonaphthalene, 1,8 dichloronaphthalene, 1,2,7,8tetrachloronaphthalene, 2,6 dichloroanthracene, 1,5,9,10tetrabromoanthracene, 2,2' dibromobiphenyl, 2,5 dichlorobiphenyl,silicon tetrachloride, tin tetrachloride, and the following.

P-Cl

Cl-P-Cl Cl-P-CH3C1 Cl-P-CH-CIC-Cl Polyvinylchloride Neoprene Vinylidenechloride polymers and copolymer with other monomers The joining agentmay be any halogenated joining agent which is effective in joiningrubber polymers.

The alkali metal compounds used for joining include, for instance, thealkyl lithiums including alkyl groups (straight and branched chain) of lto 10 or 20 or more carbon atoms, the hydrocarbon lithium catalystslisted above and the corresponding sodium and potassium compounds. Thealkali metal compounds which are soluble in a hydrocarbon solvent, suchas pentane, hexane, benzene or similar solvents are useful for forming asolution (cement) of the polymer of a diene monomer to be reacted inaccordance with the invention. The use of compounds of sodium andpotassium may present some'difficulties because of their relative lackof solubility in the hydrocarbon solvents.

The process of the invention includes reactions of one or more polymersof which at least one is dead, with one or more halogen-containingjoining reagents, in the presence of an alkali metal compound such asdescribed. The process of the invention is carried out at anytemperature at which appreciable reaction occurs, generally in the rangeof -50 or 75 C. to 275 C. and preferably in the range of 0 C. to 150 C.The reaction may be carried out under reduced pressure, atmosphericpressure or at super-atmospheric pressures. Especially when the reactionis conducted in a volatile solvent or solvent mixture containing avolatile fraction, super-atmospheric pressures are convenient to allowuse of reaction temperatures above those to which the reaction would beconfined at atmospehric pressure. The reaction temperatures required forjoining, using n-butyl lithium and a fluoride or iodide joining agent,are in general higher than that required with a chloride or bromidejoining agent. In the reaction of the invention there is normallyutilized sufiicient alkali metal compound to provide from 0.01 to l0 andpreferably 0.1 to 1.0 equivalent of alkali metal per atom of halogencontained in the halogen-containing compound. The mechanisms by whichthe reaction of the invention increases molecular weights of polymers isnot known but may involve formation of radicals of which thehalogen-containing compounds are precursors.

The conventional dead polymer results from neutralizing a live polymerby reaction with an acidic substance, water, an alcohol, an amine, astopping agent, an antioxidant or polymer stabilizer, or other stoppingagent as is known in the synthetic rubber art.

We feel that this joining reaction is caused by one electron transferfrom the alkali metal compound to the halogen compound which causes thejoining. Similarly, joining can be explainedv by a transient radicalintermediate. The products are to be distinguished from those obtainedby reaction with carbenes, as described in Lundpolymers.

berg 3,369,012; no halogen has been foundin the polymeriproducts made bythe process of this invention.

lFor'a continuous `operation,.using a ,dead polymer, :it willgenerallybeadvantageous toluse an alkyl halide in an inline mixer withalkyllithium,. orthe alkyl halide `and alkyllithium may be fed to themixer through separate lines.

The novel polymers produced by the invention from polymers Vobtained*)with hydrocarbon-litl'lium catalysts, vare-characterized byirnpro'vedprcessing properties, in comparison' withrpolymers which havenot been'reacted in acordnce witnthe invention of in comparison withsimilar polymers producedvby other catalysts, such as Ziegler'ctalystsf,"etc., and'having molecular weights comparable to Ythose ofthe novel polymers. The `novel polymers are rubbery and behave in rubbermils','Banbu1y `mixers and extruders as satisfactorily asido `emulsionpolymers or" the conventional SBR types. The novel rubber'y polymers'are' 'readily utilized" in ypractical rubber compoundswithoutadmixt'u're of naturalV rubber or conventional SBR, al-

polymers if desired'. Y

The novel 'polymers have higher average molecular weights, l"normallyaveraging percent to several hunvdredfpercent higherthari thel averagemolecular weight of the polymer' before reaction in accordance with theinventionsffhe novelpolyrne'rs are much less jlinear than'the linear'start-ing pl'ymersand are often highly branched. They have broadenedmolecular weight distribution. The

'though such other rubbers maybe mixed with the novel preferred productsare solids with reduced V(orf no) tendency to coldflowand present nopackaging or shipping problems. The novel rubberypolymers can beextensively diluted with Vl"'(a`svvitli 37.5 parts o il per 100partspolymer)y without objectionable vcold-flow.

:'"lhefpreferred rubber polymers" providewiilcanizats Y havin'g' highermoduli 'than comparable vulcaniza'tesof i comparable 'prior'art'polymers This property 'enhances the' value-:of the novel polymersfor many industrial'uses, and es'pecially'iin tiretreads and"'carcasscompositions. Surprisingly, they possess the high resiliencf'hi'gheiliciency, kl'ow running temperature, high dynamic modulus and low-`internal friction properties characterizing the "'starting'fplymers,`andbe'nc'e"are'mu'cli superior 'in these respects to vlcanizatesf ofconventional emulsion 'i The y"process ofthe" invention increases themolecular Weight* of polymers andr reduces linearity, producingbranchingrand/ or Across-linking; it can be utilized, ifdesiredt'ovcross-linl a polymer to a stage where the novel polymervdisplays vvulcanizate properties. Such novell vulcan'izateshave'jadvantages because the cross-links in their structures dcpi'rotinvolve sulfur or oxygen Vlinkages but carbon-to-carbon "cross-links.

"FIGS l and 2 are V`gel-permeation chromatograph (GsPC.) curves Yshowingthe shift in'propertiesrof polymers by joinin'gasexplained in YExample9'. Y

The invention is illustrated by the following` examples, in which partsare expressed'byweight unless otherwise indicated.

t EXAMPLE l A' series of polybutadienes was prepared in bottles bycharging 200 ml. of va"hexa'n`e solution containing 30 grams rolhalogen-containing joining agent of the invention. Data are shown inTable I.

TABLE I Mllimoles Millimoles butylbutyl lithium chloride None None 0. 84None 1. 68 0. 05 2. 20 0. l0 2. 52 0. l5 .5. 36 0. 50 4. 2 1. 0

The seven bottles were then place in a C. bath for two to six hours andagitated therein in a conventional manner. The bottles were removed fromthe bath and opened. The contents of each bottle was coagulated bymethanol in the usual manner, and each coagulum was dried. The resultingPolymers 1A and 1B were both soft and. gummy,indicating that the twopolymers were substantially identical; `Polymers 1C through 1G wereprogressively more tough and nervy, showing that the molecular weightsof these five polymers had been substantially increased by reaction withthe additional n-butyllithium and the secondary butyl chloride.

EXAMPLE 2 A seriespof bottles containing polyisoprene was prepared in amanner analogous to the manner of preparing the startingf'polybutadienepolymers of Example l, using a puried solution of isoprene in hexane,and a total of only 0.24 millimole of n-butyllithium in each bottle.Upon completion of the polymerizations, the polyisoprene in each bottlewas killed. One bottle, Bottle 2A, containing dead polyisoprene polymer,was retained as a control. Additional "butyllithium vwas added to theremaining bottles, one Aof which, Bottle 2B, was then sealed to serve asa control. To two other bottles, Bottles 2C and 2D, containing fdeadpolymer, there was added different Vamounts of secondary butyl chloride.Data are shown in'Table H. TABLE II Y Millimoles Millimoles butylbutylBottle lithium chloride None None 4.2 None 4.2 0.5 2 1 0.25

Butadiene 1,3 (BD) was polymerized in hexane solution, using kdifferentamounts of n-butyllithium (BuLi) as initiator, at 50 C. for 18 hours,and then the lithiated polymers were killed with methanol. Samples ofthe dead polymer were joined by heating with sec.butyl chloride(secaBuCl) and n-butyllithium (n-BuLi) at 70 C. for 12- hours. lnjoiningmolecules olf the dead polymer, the n-b'utyllithium was used as thebase. Details of the reactions and polymers are given in Table III. TheMooney viscosity (ML/4/ 100 C.) is given for the polymer, both beforeand after joining.

TABLE III Polymerization Joining conditions Physical properties ofpolyof BD mers Mmoles Mmoles Mmole ML/4 at Initial of sec. of n-BuLl1ML/4 at Run BuLi 100 C. polymer BuCl added 100 C. DSV l Gel 0. 75 N oneNone 0.75 0.35 1. 24 160. 2 0.75 1. 75 1 55 144 0.75 3. 50 l. 8G 145 0.75 5. 25 2. 48 156 0. 75 2. 00 2. 17 130. 5 0. 47 0. 05 1. 24 60. 3 0.47 0. 05 2 47 144. 0

1 Diluto solution viscosity. ASTM-D 1601-61, Pt 27, June 1067, page 531.

Table III shows that the dead polymer at the start of EXAMPLE 6 thejoining reaction had a Mooney viscosity value of 7 or 10, and thereaction of the dead polymer with different amounts of seo-butylchloride in the presence of different amounts of the alkali metalcompound (n-butyllithium) produced polymers of increased Mooneyviscosity values. The production of gel shows that the reaction Wassevere. The amount of gel can be controlled by varying the ratio of thealkali metal compound and the joining agent, and can be practicallyeliminated. The gel filtered through a gel screen, indicating that it isa cross-linked gel rather than an extremely high molecular weightmaterial.

EXAMPLE 4 Polybutadiene Was prepared by polymerizing butadiene- 1,3 inhexane with n-butyllithium, as initiator, at 70 C. After thepolymerization was complete, methanol was added to remove activelithium. Molecules of the dead polymer were joined by heating withn-chlorododecane at 50 C. for six hours, using 0.40 millimole ofn-butyllithium per mole ot polymer as the alkali metal compound. In thetable, the dead polymer is indicated as that of Run 4A, and the joinedpolymers are identitied as produced in Runs 4B and 4C. The amount ofchloride and initiator used in each joining reaction, and the propertiesof the polymers are recorded in Table IV.

TABLE IV Properties of final Joining reaction polymer Chloride, BuLi,ML/4 at; Williams 1 Run mmolcs mmoles DSV 100 C. Recovery None 1. 50 1.14 5 0. 08 O. 40 6. 00 1. 66 140 7. 05 0. 40 4. 50 3. 10 150 7. 60

1 In accordance with ASTM designation: D92S-56, published in ASTMStandards On Rubber Products, pages 472-474 (1957), except that testswere made at room temperature (about 23 C.), no talc was used andrecovery values are actual measurements in mm.

The increases in DSV, Mooney viscosity and Williams Recovery values showthat joining occurred.

EXAMPLE TABLE V Properties of final Joining reaction polymer chloride,BuLi, iup/4 at williams Run mmolcs mmoles DSV 100 C. Recovery None 1. 50l. 14 5 0. 06 0. 50 3. 0 1. 7l 145. 0 6. 57 l. 50 1. 50 138.

The increases in DSV, Mooney viscosity and Williams Recovery valuesshows that a joining reaction occurred.

Butadiene-1,3 was polymerized for 16 to 18 hours at 50 C. to a Mooneyviscosity (MLM/100 C.) of 17 with 0.162 millimole of n-butyllithium andthen methanol was added to react with the active lithium. The resultingsolution of the dead polymer was heated at 70 C. for 12 hours withsec-butyl chloride using n-butyllithium as the alkali metal compound.The reaction mixture was neutralized with tert-butyl alcohol. Theconditions of the reactions and properties of the products aresummarized in Table VI. Run 6A is a control produced at 70 C.

TABLE VI Properties of nal polymer n-BuLi, ML/4 at Joining reactionmmoles C. DSV Gel None 16. 5 1. 74 None 3. 0 79. 0 2. 23 None 3.0 75. 52. 51 Nono 3. 0 171. 0 4. 47 None The increases in Mooney viscosity andDSV show that joining occurred.

EXAMPLE 7 Dead polybutadiene, too soft for a Mooney determination (thatis with a Mooney viscosity of less than 5), prepared with n-butyllithiuminitiator was joined by reaction With see-butyl bromide, usingn-butyllithium as the alkali metal compound. The properties of the deadpolymer and the conditions and properties of the final product arerecorded in Table VII. The effect of the joining agent reaches a maximumand then lessens.

TABLE VII v Joining reaction Properties of polymer Brornide, BuLi, Hrs.at ML/4 at Williams mmoles mmole 70 C. 100 C. Recovery The increases inMooney viscosity and Williams Recovery show that joining occurred.

EXAMPLE 8 at 70 C. one millimole of n-butyllithium and .8 mil1imole ofsec-butyl chloride was added. Within several hours a copolymer with aMooney viscosity (ML/4/ 100 C.) of 120 was obtained.

EXAMPLE 9 Butadiene-1,3 was polymerized to a Mooney viscosity (MLM/100C.) of 5. The reactions were neutralized with suflicient methanol toobtain dead polymer. In two different runs, this polymer was joinedusing two different ratios of sec.butyl chloride as the joining agentand n-butyllithium as the alkali metal compound. These are given as themillimoles of chlorine (Cl) and lithium (Li) per 100 grams of butadiene(Bd). The joining reactions were carried out at 70 C. The differentpolymers were examined by gel-permeation chromatography and the curvesobtained are reproduced as FIGS. 1 and 2. In each of the sets of curves,the control is plotted with circles and the curves obtained with thepolymers produced using the conditions shown in the respective legends,are plotted with squares and triangles. The curves of the joinedpolymers show a shift from a lower molecular weight to a highermolecular weight. The long, high-molecular-weight tails are typical ofthe distribution expected for random cross-linking. It is possible toproduce gel in such polymers by adding sucient joining agent and alkalimetal compound. By adding excessive amounts completely insolublepolymers are obtained. This and the shapes of the curves are indicativeof predominantly random cross-linking reactions.

The novel polymers can be blended with other known polymers to provideuseful commercial compositions for fabrication into useful shapes andarticles. The novel rubbery polymers are advantageously blended withknown rubbers (e.g., natural rubber, butadiene-styrene copolymer,polybutadiene, polyisoprene, isoprene-isobutylene copolymer,chloroprene, isoprene-styrene copolymer), with or without extendingoils, for forming vulcanizates of great technical importance. The novelrubbery polymers are advantageouly compounded with the known reinforcingcarbon blacks to produce useful commercial stocks, which may alsocontain one or more additional rubbery polymers, and may also contain to100 p.h.r. (parts per 100 parts of the rubber) of extending oil orplasticizer. Sulfur and other known vulcanizing agents for naturalrubber and the commencial synthetic rubbers are useful for formingvulcanizable stocks containing a novel polymer of the invention. Knownantioxidants, stabilizers and antiozonants for natural and commercialsynthetic rubbers ind similar utility in compositions containing thenovel polymers of the invention. Known methods of mixing, forming,fabricating and curing compositions of natural and commercial syntheticrubbers are applicable to and useful with compositions containing thenovel polymers of the invention. The novel polymers of the invention are10 especially useful in pneumatic tire tread, sidewall and carcasscompositions, and the considerations of this paragraph are especiallyrelevant to the use of the novel polymers in tires.

I claim:

1. The process of making a relatively high molecular weight, non-linearrubber polymer from one or more dead, relatively low molecular weightpolymers derived at least in part from a diene monomer, which processcomprises treating the dead polymer in the presence of a metalatedaliphatic or cyclic hydrocarbon selected from the class consisting ofsodium hydrocarbons, potassium hydrocarbons and lithium hydrocarbonswith a joining agent which is from the class consisting of (a)halogen-containing silicon and tin hydrocarbons, (b) halogenatedhydrocarbons and (c) halogenated hydrocarbons substituted with a groupselected from the class consisting of ketone, aldehyde, ether, hydroxy,oxide, nitro-vinyl, ester, anhydride, amine, acid, thio, sulfonate andsulfide groups, using 0.1 to 10 equivalents of alkali metal per atom ofhalogen in the joining agent.

2. The process of claim 1 in which the polymer is polybutadiene.

3. The process of claim 1 in which the polymer is polyisoprene.

4. The process of claim 1 in which the polymer is a. copolymer ofbutadiene and styrene.

5. The process of claim 1 in which the alkali metal compound is a loweralkyllithium.

6. The process of claim 1 in which the joining agent is secondary butylchloride.

, 7. The process of claim 1 in which the polymer is obtained with alithium-based catalyst.

8. The process of claim 1 in which the polymer is obtained withbutyllithium and short-stopped with alcohol.

9. The process of claim 1 in which the rubber polymer is from the classconsisting of polybutadiene, polyisoprene and copolymers thereof withstyrene, the metalated hydrocarbon is butyllithium and the joining agentis an aliphatic halide of chlorine or bromine.

References Cited y UNITED STATES PATENTS 3,078,254 2/ 1963 Zelinski etal. 260-45.5 3,135,716 6/1964 Uraneck et al. 260-45.5 3,281,383 10/1966Zelinski et al. 26o-23.7 3,318,862 5 1967 Hinton 260-94.2 3,492,3 69 1/1970 Naylor 2605879 JAMES A. SEIDLECK, Primary Examiner W. F. HAMROCK,Assistant Examiner U.S. Cl. X.R.

260-82.1, 94.7 R, 94.7 (HA, 96 R P04050 UNITED STATES PATENTA OFFICE 569CERTIFIQATE 0F CORRECTION Pater-1t No.. 316571206 w I Y Deted v uwnventor( s) Adel F- Havlasa v It is certified-that error appears inl theabove-identified patent and that said Letters Patent are herebycorrected as shown below: v

Col. 2., line 5, "pressure"l n* second occurrence, should read Npressures Col. 5, line N7, "weight" should read weights j co1. 7,Table-1.11, 'sixth column, lastvnne, #2.1m should read 2.l+8`0 Signedand sealed this 26th day of September 19.72.A

(SEAL) Attest: o

EDWARD M.FLETCH1;IR,JR. ROBERT GOTTSCHALK Attestng Officer Commissionerof Patents'

